Added support array attributes (#798)

* Added support array attributes

* Changed function signature for AsArray attribute

* Fixed code comments for array attributes

* Fixed typos in comments in value.go

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

api/kv/key.go

@@ -158,3 +158,16 @@ func (k Key) Uint(v uint) KeyValue {
 func (k Key) Defined() bool {
 	return len(k) != 0
 }
+
+// Array creates a KeyValue instance with a ARRAY Value.
+//
+// If creating both key and a array value at the same time, then
+// instead of calling kv.Key(name).String(value) consider using a
+// convenience function provided by the api/key package -
+// key.Array(name, value).
+func (k Key) Array(v interface{}) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: value.Array(v),
+	}
+}

api/kv/kv.go

@@ -95,6 +95,12 @@ func Uint(k string, v uint) KeyValue {
 	return Key(k).Uint(v)
 }
 
+// Array creates a new key-value pair with a passed name and a array.
+// Only arrays of primitive type are supported.
+func Array(k string, v interface{}) KeyValue {
+	return Key(k).Array(v)
+}
+
 // Infer creates a new key-value pair instance with a passed name and
 // automatic type inference. This is slower, and not type-safe.
 func Infer(k string, value interface{}) KeyValue {
@@ -109,6 +115,8 @@ func Infer(k string, value interface{}) KeyValue {
 	rv := reflect.ValueOf(value)
 
 	switch rv.Kind() {
+	case reflect.Array, reflect.Slice:
+		return Array(k, value)
 	case reflect.Bool:
 		return Bool(k, rv.Bool())
 	case reflect.Int, reflect.Int8, reflect.Int16:

api/kv/value/type_string.go

@@ -17,11 +17,12 @@ func _() {
 	_ = x[FLOAT32-6]
 	_ = x[FLOAT64-7]
 	_ = x[STRING-8]
+	_ = x[ARRAY-9]
 }
 
-const _Type_name = "INVALIDBOOLINT32INT64UINT32UINT64FLOAT32FLOAT64STRING"
+const _Type_name = "INVALIDBOOLINT32INT64UINT32UINT64FLOAT32FLOAT64STRINGARRAY"
 
-var _Type_index = [...]uint8{0, 7, 11, 16, 21, 27, 33, 40, 47, 53}
+var _Type_index = [...]uint8{0, 7, 11, 16, 21, 27, 33, 40, 47, 53, 58}
 
 func (i Type) String() string {
 	if i < 0 || i >= Type(len(_Type_index)-1) {

api/kv/value/value.go

@@ -17,7 +17,9 @@ package value
 import (
 	"encoding/json"
 	"fmt"
+	"reflect"
 	"strconv"
+	"strings"
 	"unsafe"
 
 	"go.opentelemetry.io/otel/api/internal"
@@ -34,6 +36,8 @@ type Value struct {
 	numeric  uint64
 	stringly string
 	// TODO Lazy value type?
+
+	array interface{}
 }
 
 const (
@@ -46,6 +50,7 @@ const (
 	FLOAT32             // 32 bit floating point value, use AsFloat32() to get it.
 	FLOAT64             // 64 bit floating point value, use AsFloat64() to get it.
 	STRING              // String value, use AsString() to get it.
+	ARRAY               // Array value of arbitrary type, use AsArray() to get it.
 )
 
 // Bool creates a BOOL Value.
@@ -130,6 +135,32 @@ func Uint(v uint) Value {
 	return Uint64(uint64(v))
 }
 
+// Array creates an ARRAY value.
+func Array(array interface{}) Value {
+	switch reflect.TypeOf(array).Kind() {
+	case reflect.Array, reflect.Slice:
+		isValidType := func() bool {
+			// get array type regardless of dimensions
+			typeName := reflect.TypeOf(array).String()
+			typeName = typeName[strings.LastIndex(typeName, "]")+1:]
+			switch typeName {
+			case "bool", "int", "int32", "int64",
+				"float32", "float64", "string",
+				"uint", "uint32", "uint64":
+				return true
+			}
+			return false
+		}()
+		if isValidType {
+			return Value{
+				vtype: ARRAY,
+				array: array,
+			}
+		}
+	}
+	return Value{vtype: INVALID}
+}
+
 // Type returns a type of the Value.
 func (v Value) Type() Type {
 	return v.vtype
@@ -183,11 +214,18 @@ func (v Value) AsString() string {
 	return v.stringly
 }
 
+// AsArray returns the array Value as an interface{}.
+func (v Value) AsArray() interface{} {
+	return v.array
+}
+
 type unknownValueType struct{}
 
 // AsInterface returns Value's data as interface{}.
 func (v Value) AsInterface() interface{} {
 	switch v.Type() {
+	case ARRAY:
+		return v.AsArray()
 	case BOOL:
 		return v.AsBool()
 	case INT32:
@@ -211,6 +249,8 @@ func (v Value) AsInterface() interface{} {
 // Emit returns a string representation of Value's data.
 func (v Value) Emit() string {
 	switch v.Type() {
+	case ARRAY:
+		return fmt.Sprint(v.array)
 	case BOOL:
 		return strconv.FormatBool(v.AsBool())
 	case INT32:

api/kv/value/value_test.go

@@ -40,6 +40,12 @@ func TestValue(t *testing.T) {
 			wantType:  value.BOOL,
 			wantValue: true,
 		},
+		{
+			name:      "Key.Array([]bool) correctly return key's internal bool values",
+			value:     k.Array([]bool{true, false}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []bool{true, false},
+		},
 		{
 			name:      "Key.Int64() correctly returns keys's internal int64 value",
 			value:     k.Int64(42).Value,
@@ -94,6 +100,66 @@ func TestValue(t *testing.T) {
 			wantType:  bli.unsignedType,
 			wantValue: bli.unsignedValue,
 		},
+		{
+			name:      "Key.Array([]int64) correctly returns keys's internal int64 values",
+			value:     k.Array([]int64{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []int64{42, 43},
+		},
+		{
+			name:      "KeyArray([]uint64) correctly returns keys's internal uint64 values",
+			value:     k.Array([]uint64{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []uint64{42, 43},
+		},
+		{
+			name:      "Key.Array([]float64) correctly returns keys's internal float64 values",
+			value:     k.Array([]float64{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []float64{42, 43},
+		},
+		{
+			name:      "Key.Array([]int32) correctly returns keys's internal int32 values",
+			value:     k.Array([]int32{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []int32{42, 43},
+		},
+		{
+			name:      "Key.Array([]uint32) correctly returns keys's internal uint32 values",
+			value:     k.Array([]uint32{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []uint32{42, 43},
+		},
+		{
+			name:      "Key.Array([]float32) correctly returns keys's internal float32 values",
+			value:     k.Array([]float32{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []float32{42, 43},
+		},
+		{
+			name:      "Key.Array([]string) correctly return key's internal string values",
+			value:     k.Array([]string{"foo", "bar"}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []string{"foo", "bar"},
+		},
+		{
+			name:      "Key.Array([]int) correctly returns keys's internal signed integral values",
+			value:     k.Array([]int{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []int{42, 43},
+		},
+		{
+			name:      "Key.Array([]uint) correctly returns keys's internal unsigned integral values",
+			value:     k.Array([]uint{42, 43}).Value,
+			wantType:  value.ARRAY,
+			wantValue: []uint{42, 43},
+		},
+		{
+			name:      "Key.Array([][]int) correctly return key's multi dimensional array",
+			value:     k.Array([][]int{{1, 2}, {3, 4}}).Value,
+			wantType:  value.ARRAY,
+			wantValue: [][]int{{1, 2}, {3, 4}},
+		},
 	} {
 		t.Logf("Running test case %s", testcase.name)
 		if testcase.value.Type() != testcase.wantType {

sdk/trace/span.go

@@ -26,6 +26,7 @@ import (
 
 	"go.opentelemetry.io/otel/api/global"
 	"go.opentelemetry.io/otel/api/kv"
+	"go.opentelemetry.io/otel/api/kv/value"
 	apitrace "go.opentelemetry.io/otel/api/trace"
 	export "go.opentelemetry.io/otel/sdk/export/trace"
 	"go.opentelemetry.io/otel/sdk/internal"
@@ -103,7 +104,10 @@ func (s *span) SetAttributes(attributes ...kv.KeyValue) {
 }
 
 func (s *span) SetAttribute(k string, v interface{}) {
-	s.SetAttributes(kv.Infer(k, v))
+	attr := kv.Infer(k, v)
+	if attr.Value.Type() != value.INVALID {
+		s.SetAttributes(attr)
+	}
 }
 
 func (s *span) End(options ...apitrace.EndOption) {
@@ -293,7 +297,9 @@ func (s *span) copyToCappedAttributes(attributes ...kv.KeyValue) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	for _, a := range attributes {
-		s.attributes.add(a)
+		if a.Value.Type() != value.INVALID {
+			s.attributes.add(a)
+		}
 	}
 }